Pipe cutter



Patented Nov. 1, 1938 UNITED STATES PATENT OFFICE 9 Claims.

This invention relates to a pipe cutter.

It is an object of the invention to provide an inside pipe cutter adapted to cut by rotation and embodying novel means whereby the cutter may be anchored in the pipe to be out, released, and reanchored if desired, for another out.

It is another object of the invention to provide, in a pipe cutter, novel means for actuating the cutters into, and maintaining them in, cutting relation with the pipe to be severed.

It is another object of the invention to provide in a pipe cutter, means. including a confined body of liquid through which the weight of the operating string may be applied to actuate the cutters outwardly into cutting position and whereby the cutters may be automatically controlled to regulate the feed thereof to the pipe to be cut.

A further object of the invention is to provide an inside pipe cutting tool adapted to cut by rotation and embodying novel means, which are automatically regulated, for feeding the cutters to the work.

With the above and other objects in View the invention has particular relation to certain novel features of construction, operation and arrange ment of parts, an example of which is given in this specification and illustrated in the accompanying drawings, wherein- Figure 1 shows a side view, partly in section, of the upper end of the tool, shown in inactive or non-cutting position.

Figure 2 shows a side view, partly in section, of the lower end thereof.

Figure 3 shows a cross-sectional view taken on the line 3-3 of Figure 1.

Figure 4 shows a side View, partly in section, of the upper end of the tool shown in active, or cutting position.

Figure 5 shows a side view, partly in section, of the lower end thereof, and

Figure 6 shows a side View, partly in section, of the complete tool, shown in inactive, or non-cutting position.

Referring now more particularly to the drawings wherein like numerals of reference designate similar parts in each of the figures, the numeral l designates the tubular cutter body whose lower end is inwardly thickened forming an inside, annular shoulder 2 providing a spring seat and which has an inside, annular groove 3 to receive a packing and beneath said groove the body is pro vided with the downwardly and outwardly diverging guide ways 4.

Attached to the. upper end of the body there is the tubular gland 5 having the inside, annular groove 6 to receive a packing.

In the cutter body there is a tubular cutter actuator 1 whose upper end has an external, annular flange 8. A strong coil spring 9 surrounds the actuator and is supported on the seat 2. The flange 8 rests on this spring and thereby supports the actuator. A packing I0 is seated in the groove 3 and closely surrounds the actuator forming a fluid tight joint between it and the body. There are the cutters ll whose upper ends are pivotally attached to the lower end of the actuator and whose lower ends work through the guides 4.

The body I encloses a cylindrical chamber I 2 in which the piston I3 is mounted to reciprocate. Extending upwardly from the piston, through the gland 5, there is a tubular stem l4 which is closely surrounded by a packing l5 seated in the groove 6. A tubular operating string [6 is attached to the upper end of the stem I4 and extends to the ground surface whereby the tool may be lowered, elevated and operated.

A tubular stem I1 is attached to the lower end of the piston l3 and extends downwardly into the cutter actuator 1 and is closely surrounded therein by a packing l8 seated in the groove [9 of said actuator. Fluid tight joints are thus pro vided between the stem l4 and the gland 5 as well as between the actuator l and the body I and also between said actuator and the stem IT.

The piston i3 is provided with a channel 2|] therethrough from the lower to the upper end thereof and the upper end of this channel is reduced and extends through the plug 2| screwed into the upper end of said piston as more clearly shown in Figure 4. The piston l3 also has a channel 22 leading from the upper to the lower end thereof of somewhat greater capacity than the channel 20. The upper end of the channel 22 is provided with a valve seat 23 screwed into the upper end of the piston I3 and which is controlled by the downwardly opening back pressure valve 24 as shown in Figures 1 and 4.

Surrounding the stem I1 and suitably anchored thereto there is a saucer-shaped, flexible disc 25 whose free margin rests against the lower end of the piston I3. The lower end of the piston has a radial guide way 26 in which the lower end of the channel 20 terminates, as shown in Figure 3 and a valve 21 is mounted to move in said guide way and is fastened to the margin of the disc 25.

Screwed into the lower end of the body I there is a tubular gland 28 whose lower end has the external, annular flange 29. Beneath said gland there is a tubular expander 30 whose upper end has an external, annular flange 3I and whose lower end has the external downwardly tapering face 32. Between the flanges 29, 3I there is an antifriction bearing assembly 33 which is sur rounded and enclosed by the circular housing 34. Upper and lower retaining rings 35, 36 are secured to the inside of the housing 34 at the upper and lower ends thereof, respectively, and which embrace the flanges 29, 3| whereby the expander 30 is supported and allowed to swivel relatively to the body I.

There is a tubular mandrel 31 to the lower end of which is attached a tubular guide 38. This guide has the yieldably mounted, outwardly extended, frictional gripping members 39 mounted therein adapted to grip the pipe 40 to be cut as illustrated in Figure 4.

Secured to the upper end of the guide 38 are the upstanding flexible arms 4| whose upper ends carry the pipe engaging slips 42. The outer surfaces of these slips are preferably toothed as shown and their inner surfaces are upwardly and outwardly tapered to be engaged by the down wardly tapering face 32 of the expander 30, when the expander is lowered, whereby the jaws 42 will be forced into secure gripping relation with the pipe 40 as shown in Figure 5 to support the cutting tool while the tool is operating. The upper end of the mandrel 31 has an external, annular flange 43 thereon adapted to engage the upper end of the gland 28 when the mandrel is in its lower position, as shown in Figure 2. The body I has an inside key 44 whose lower end rests against the upper end of the flange 43, when the tool is in inoperative position so that while going into the well the mandrel 31 cannot move upwardly relative to the body to expand the gripping jaws 42. The flange 43 has an external keyway 45 adapted to receive the key 44 when in alignment therewith whereby the mandrel 31 is permitted to move upwardly, as hereinafter explained, so as to locate the flange 43 above the key 44.

The tool is assembled as shown in Figure 1 and 2 and the chamber I2, which extends from the lower end of the gland 5 to the shoulder 2 is filled with oil or other suitable liquid. The mandrel 31 is turned to position to carry the keyway 45 out of alignment with the key 44 with the flange 43 located beneath said key. As so assembled the tool is let down into the pipe to be out. While being lowered the gripping members 39 will frictionally engage the inside wall of the pipe 40. When it is desired to make a cut the operating string I6 may be turned to the right and when the key 44 aligns with the keyway 45 the body I will move downwardly, said key passing through said keyway and the expander 30 wedging in between and expanding the slips 42 into secure engage-- ment with the pipe as shown in Figure 5. The tool will thereby be anchored and supported in the pipe to be cut. While locating the tool in the pipe the piston I3 will be at the upper end of the chamber I2. The operating string I6 may now be allowed to move downwardly, gradually and the pressure of the liquid beneath the piston I3 will react against the upper end of the cutter actuator 1, forcing the same downwardly and compressing the spring 9 thus feeding the cutters II through the guide ways 4 andinto contact with the pipe to be out. The operating string is in the meantime rotated and the stem I4, having a splined connection 46, with the gland 5, a rotation of the operating string will be imparted also to the body I and to said cutters and as the cutters are gradually forced outwardly by the downward pressure against the actuators 1 they will gradually cut into the pipe until it is severed.

Screwed on to the stem I4 there is a nut 41 which is adjustable thereon and which may be locked in any desired position by the lock nut 48. When the out has been completed, the lock nut 48 will land on an antifriction washer 49 on the upper end of the gland 5 to limit the downward movement of the piston I3 and the outward movement of the cutters I I.

While the cut is being made the piston I3 will gradually move downwardly increasing the pressure of the fluid beneath it in the chamber I2 and this pressure will react against the actuator 1 to feed the cutters to the work as above stated and said liquid will gradually leak through the channel 20 to allow this downward movement of the piston. Should the cutters encounter an obstruction in the pipe being cut, or unusually hard material to arrest the downward movement of the actuator the disc 25 will land on the upper end of the actuator and the disc will be expanded, or partly flattened out so as to carry the valve 21 across the lower end of the channel 20 to block said channel to prevent the further downward movement of the piston I3. There will be less pressure of liquid against the actuator than there is against the lower end of the piston I3 for the reason that the piston has the greater area exposed to the pressure so that when the channel 20 is closed by the valve 21 the cutters will not be actuated further outwardly until they have had the opportunity to cut away the obstruction or hard material encountered by them whereupon, as the obstruction is relieved, the pressure in the chamber I2 beneath the piston will resume gradually feeding the cutters outwardly to the work. As said actuator moves on downwardly the disc 25 will resume its original shape and withdraw the valve 21 from obstructing position thus leaving the channel 20 open and the cutting operation will continue as before. The feed of the cutters to the work will be thus automatically controlled.

Upon upward movement of the piston in the cylindrical chamber I2 the valve 24 will open and. permit the liquid above said piston to quickly pass through the channel 22 into the chamber I2 beneath said piston and thereupon the valve 24 will again close.

The drawings and description disclose what is now considered to be a preferred form of the invention by way of illustration only, while the broad principle of the invention will be defined by the appended claims.

What I claim is:

1. A pipe cutter shaped to enter a pipe and comprising a cutter body formed with a chamber therein and having a cutter guide therethrough, means for anchoring the body to said pipe, a cutter actuator in the body, a cutter working through the guide and connected to the actuator, liquid in the chamber to the pressure of which one end of the actuator is exposed, an operating string terminating in a piston in the chamber adapted, upon downward movement, to subject said liquid to pressure and means normally tending to hold the cutter retracted.

2. A pipe cutter comprising a cutter body shaped to enter a pipe in a well and having a chamber therein and a cutter guide through the wall of the body, means for anchoring the body to the pipe, liquid in the chamber, a cutter actuator in the body exposed to the liquid, a cutter working through the guide and connected to the actuator, an operating string, a piston in the chamber connected to the string and arranged to apply pressure to the liquid, upon downward movement of the string to move the actuator downwardly and to thereby actuate the cutter outwardly into cutting relation with the pipe and a yieldable member acting against the actuator to retract the cutter upon relief of said pressure.

3. A pipe cutter comprising a cutter body shaped to enter a pipe in a well and having a chamber therein and a cutter guide through the wall of the body, means for anchoring the body to the pipe, liquid in the chamber, a cutter actuator in the body exposed to the liquid, a cutter working through the guide and connected to the actuator, an operating string, a piston in the chamber connected to the string and arranged to apply pressure to the liquid, upon downward movement of the string, to move the actuator downwardly and to thereby actuate the cutter outwardly into cutting relation with the pipe and a yieldable member acting against the actuator to retract the cutter upon relief of said pressure, and means for automatically regulating the pressure against the actuator.

4. A pipe cutter adapted to cut by rotation and comprising a cutter body shaped to enter a pipe in a well and having a chamber therein and a cutter guideway therethrough, liquid in the chamber, means for anchoring the body to the pipe, a cutter actuator in the body exposed to the liquid in the chamber, a cutter connected to the actuator and working through said guideway, a piston in the chamber effective upon downward movement to apply pressure to the liquid, said piston having liquid passageways therethrough, a downwardly opening valve controlling one of said passageways, an operating string having a slidable but non-rotatable connection with the body and connected to the piston, means arranged to close the other passageway upon a predetermined pressure of said liquid and means for retracting the cutter upon relief of said pressure.

5. A pipe cutting tool adapted to cut by rotation and comprising a cutter body shaped to enter the pipe to be cut, means for anchoring the tool to the pipe, cutting means in the body, means normally holding the cutting means inactive or retracted, mechanical means for feeding the cutting means to the work and hydraulically controlled means for automatically controlling the feed of the cutting means.

6. A pipe cutter comprising a cutter body shaped to enter a pipe in a well and having a chamber therein and a cutter guide, means for anchoring the body to the pipe to be cut, liquid in the chamber, a cutter actuator, a cutter arranged to be moved outwardly by the guide into cutting relation with the pipe to be cut, an operating string, a piston in the chamber arranged to be moved downwardly upon downward movement of the string to apply pressure to the liquid to control the feed of the cutter and a yieldable member acting against the actuator to retract the cutter upon relief of said pressure.

7. A pipe cutter adapted to cut by rotation and comprising a cutter body shaped to enter a pipe in a well and having a chamber therein and a cutter guide, liquid in the chamber, means for anchoring the body to the pipe, a cutter actuator associated with the body, a cutter connected to the actuator and working against said guide, a

piston in the chamber effective upon downward movement to apply pressure to the liquid and to actuate the cutter, said piston having liquid passageways therethrough, a downwardly opening valve controlling one of said passageways, an operating string having a slidable but non-rotatable connection with the body and connected to the piston, means arranged to close the other passageway upon a predetermined pressure of said liquid and means for retracting the cutter upon relief of said pressure.

8. A pipe cutting tool adapted to cut by rotation and comprising a cutter body shaped to enter the pipe to be cut, means for anchoring the tool to the pipe against downward movement, cutting means on the body, means normally holding the cutting means inactive or retracted, mechanical means for feeding the cutting means to the work, hydraulically controlled means for controlling the feed of the cutting means, said hydraulically controlled means including a confined body of liquid, a piston operable against the liquid and having a by-pass whereby a retarded movement of the piston will be effected.

9. A pipe cutting tool adapted to cut by rotation and comprising a cutter body shaped to enter the pipe to be cut, means for anchoring the tool to the pipe against downward movement, cutting means, means normally holding the cutting means retracted, means for moving the cutting means downwardly, means for moving the cutting means outwardly, upon such downward movement, into active position in cutting relation with the pipe to be severed, a cylinder, liquid in the cylinder, a piston operable against the liquid in the cylinder for automatically controlling the feed of the cutting means to the work.

FRED N. OSMUN. 

